hey guys!
im new to this forum and also new to kawasaki. i bought an '06 klx 250s and love it so far except for its lack of power. i've been looking at all the mods i can do and i want to change to a 13 t sprocket, remove airbox cover, possibly re-jet the carb, and modify the stock exhaust. does anyone have info on what carb kit to buy? also any pics and/or info on drilling out the stock exhaust would be great. THANKS!

 

the dynojet jet kit for the klx300 works fine. search "exhaust" at the bottom of the main page and you'll find what you need.

 

Nope I got no information, I paid my dealer/mechanic to do all my work, and he's a racer, so I think he just maxed everything out. Hmmm maybe he did that because I'm HUGE!!!!!!!!!!! Oh and welcome to the site. Congrats on the 06, after all its the first year offered here in the states, and so we all know that the 06 will always be worth more right guys? [8D] [sm=icon_stickpoke.gif][sm=icon_cheers.gif]

 

I tried the drilling of the stock exhaust- used a 1/2 in drill bit in the end of the pipe. Not much help. Then I put on a four stroke works header- much better- so I also change the muffler. That really made the bike hit in the mid upper rpms. I also removed the air box lid- installed a dynojet kit for a klx300- changed the crankcase vent to 1/2 hose, and added a 13t counter shaft. This has made a very nice power increase.

I also changed the stock tank to a clark- I found when riding hard I hit reserve around 45 miles..

The dyno jet kit comes with good instructions. take your time it is not hard to do.

 

Welcome to the forum If you change anything in the air box or exhaust you HAVE to rejet the carb.... I would suggest changing the Snorkel and not removing the air box lid it makes a lot of noise and unless you change to a larger carb you really are hurting hte problem that let way to much air in ..... I know a lot of people think it helps but unless you can get more air flow and fuel through the carb it does not help and the stock diaphram carb will never handle that much air ......and remember without head work and cams the little 250 can only flow so much air also.....IMO Replace the snorkel and get a good muffler and jet the carb and you will be pleased

 

Pretty much everything you want to know is in a thread at the top called "mod day". Don't forget to click on the link to HMF Engineering. If you change the exhaust, you must rejet. If you open up the airbox and rejet, you must change the exhaust. Good luck, and have fun!

 

Hey Bad Bear, are you saying that if I put my air box lid back on the bike it won't make a difference? What about some of those drill and snap in air deals. And the noise? I don't hear anything except the Muzzy!!

 

300 klx jet kit and i think i used the N1TC needle, big gun exhaust, k+n air filter, no snorkle very happy with the results, as long as you rejet,airfilter,and aftermarket exhaust u wont be disapointed

 

Hey Deej I'm not saying it won't make a difference I'm just saying completely removing the lid makes a lot of noise under seat and you can only get so much air and fuel through the stock carb and head ..... I have the larger snorkel and full exhuast and jetting.....After years of racing and installing bigger valves and cams and head work I have learned a little about over kill when using stock parts....That is all I'm saying....Yes it makes a difference but only to a point .....The best performance upgrade you can ever get is by having head work and cams but that always cost the most and no one does it......For example I raced an old KZ1000 with a 1200 kit and small 33 mm carbs very outdated when my buddies used 38 to 40's they had 1425cc kit and stock head .....I went faster and made more power from the 1200 and older smaller carbs BUT I had a $5000 cylinder head .....Having a 40 mm carb and a stock valve won't work very well..... Most people always over carb motorcycles and cars ...every vehicle is different so nothing ever is the same its the same old thing just try to figure the best mods across the board....and our stock carb is poor at best but I think with the mods we do or I have done make the bike fine for what it is........I think you have seen my video of my last drag bike that engine was a 1425cc with carbs I used on the street just 36 mm MIK Pumpers everyone else was using 40 to 44 mm Fast By Gast Race carbs I have very little head work done and mild cams and it would run 8.60 on gas with small hit of NOS it would run 8.00's but the cylinder head was flow benched and everything was matched to work properly....I hope this helps So if you put your lid on the way your jetted it will be to rich BUT if you put it on and lean it out the engine will make about the same power with stock top end that is all I was saying

 

Thanks man, the way you wrote that up makes sense and even a noob like me can understand it. Thanks again.